Apparatus for filling bags with flowable bulk material and method of adjusting the apparatus

Abstract

Apparatus for filling discrete open or valve type bags with metered quantities of flowable bulk material has a gravity flow duct the upper end of which receives metered quantities of bulk material and the lower end of which discharges successive metered quantities into discrete bags. The rate of gravity flow of bulk material in the duct is regulatable by an adjustable flow restrictor which is adjusted, each time a different bulk material is gathered into metered quantities, in such a way that the rate of flow is just below that rate which causes the descending material to clog the duct. This is ascertained by starting with an adjustment at a rate well below that which results in clogging and by stepwise increasing the rate until the period of discharge of a metered quantity abruptly increases to thus indicate that the duct is being clogged. The rate of discharge is then reduced to a value at least slightly below the rate at which clogging occurs to thus ensure that the periods of time which elapse during discharge of metered quantities of bulk material into discrete bags are as short as possible without risking clogging of the duct.

I claim: 
     
       1. A method of adjusting an apparatus for filling bags with flowable bulk materials wherein successive metered quantities of bulk material are gathered at a level above a gravity flow duct, the duct having an open upper end for the admission of bulk material therein and a lower end which discharges bulk material into discrete bags, and the duct being clogged by descending bulk material when the rate of gravity flow therein rises to a predetermined rate, the apparatus including adjustable flow restricting means for varying the rate of flow in the duct, means for monitoring and evaluating the periods of time which elapse during gravity flow of successive metered quantities of bulk material into discrete bags, and motor means for the flow restricting means operatively associated with the monitoring and evaluating means, said method comprising the steps of monitoring the periods of time which elapse during gravity flow of successive metered quantities into discrete bags; increasing the rate of flow of successive metered quantities, beginning with a first rate below said predetermined rate, whereby the monitored periods become shorter with each increase of said rate, until the rate of flow reaches said predetermined rate with attendant abrupt lengthening of the monitored period; and thereupon decreasing the rate of flow with attendant abrupt shortening of the monitored period. 
     
     
       2. The method of claim 1, further comprising the steps of comparing the monitored periods and automatically initiating said rate decreasing step when said comparing step indicates said abrupt lengthening of the monitored period. 
     
     
       3. The method of claim 1, wherein said rate decreasing step includes reducing the rate below said predetermined rate by a predetermined value. 
     
     
       4. The method of claim 3, wherein said predetermined rate exceeds said first rate by a value greater than said predetermined value. 
     
     
       5. The method of claim 1, wherein said first rate is sufficiently below said predetermined rate to ensure that the gravity flow at such first rate does not entail a clogging of the gravity flow duct with descending bulk material. 
     
     
       6. The method of claim 1 of adjusting an apparatus for filling bags with different flowable bulk materials, further comprising the step of repeating said monitoring, increasing and decreasing steps upon each change of flowable bulk material. 
     
     
       7. The method of claim 6, further comprising the step of manually generating a signal to initiate repetition of said monitoring, increasing and decreasing steps. 
     
     
       8. The method of claim 1, wherein said rate increasing step includes increasing said rate at predetermined intervals. 
     
     
       9. The method of claim 8, wherein said intervals are identical intervals. 
     
     
       10. The method of claim 8, further comprising the step of gathering successive metered quantities of bulk material at said predetermined intervals.